I understand this is a complex issue but I wonder if someone here can shed some light on the current understanding of this situation.
I am a Portuguese father of two living in Germany. My wife is German. I have two children (aged 5 and 7). Both were born in England. Until ages 2.5 and 4.5 (while we were still in England) I talked to them in Portuguese, they would listen to English during their daily lives and my wife spoke German. They were trilingual in the sense that they understood Portuguese and German but they spoke mainly English.
Once we came to Germany, since they lost any English connection I started speaking English to them, my wife kept speaking German but now they hear German in their daily lives.
The problem is that they mostly lost their Portuguese and their English is rather poor as I am their sole source of English. Their German is close to native now but I don't speak German properly, having trouble understanding what they say.
Is it possible for children to gain fluency in a language (in this case Portuguese) if I started speaking Portuguese to them (therefore dropping English), given I would be their sole source of Portuguese and as a full time worker I only spend weekends and evenings with them?
Their English will be fine - they had early exposure, they have parents who presumably speak it to each other, they learn it in school, they will use it in the real world. In fact with solid knowledge of a typical Germanic language and a Romance language they will be stronger in the literary English language than most native English speakers.
– Adam Bittlingmayer Jun 12 '18 at 12:31